I did find the ladder but sadly, I fell in the water with a very large amount of zombies behind me and was unable to get away from them...   

I found out what to do but the water movement is a little touchy, like kind of hard to go through, I enjoy it but it was still giving me some problems at times, mainly when moving from water onto the land.

This map is good slightly glitchy at times, but all maps are, I'm thoroughly enjoying it but cannot find out what to do with the parts for the life of me.